On something like 1095, I've often followed the white rouge with just a few (< 5) passes on green, used on a leather belt as a hanging strop. I've also liked this routine with 420HC. Gives it an extra 'nudge' into tree-topping, hair-popping sharpness.
I'd look at it in terms of aggessiveness, versus only fineness. Sometimes a larger grit will work less aggressively, if it's either softer or differently shaped (or both). For example, red compound will likely be somewhat larger in particle size, but nowhere near as hard or aggressive as chromium oxide (green) or some 'white' compounds in aluminum oxide (also more aggressive than green, BTW). I think the 'blue' is usually a very fine aluminum oxide (may be called a 'rouge').
Given your list, I'd likely rank them this way, from most aggressive to least aggressive:
white (if AlOx) > blue (assuming AlOx) > green > red.
Red compound ('red rouge', a.k.a. iron oxide) is usually used for softer metals, like jewelry. Many modern cutlery steels will be harder than red, so it's often not very aggressive, and even ineffective on knife edges. A bare leather strop would likely work as well, maybe better.
Some 'white' compounds will be something like tin oxide or even talc, which are less aggressive even than the red compound, used for polishing things like jewelry or plastics.
David
